Adhesive applying apparatus and method



Oct. 1, 1963 .L. E. LA BOMBARD ADHESIVE APPLYING APPARATUS AND METHOD 2 Sheets-Sheet 1 Filed Sept. 19, 1960 IJV-IFJIII 1 INVENTOR. LEON E. LABOMBARD BY P 1' PW ATTORNEYS Oct. 1, 1963 1:. LA BOMBARD ADHESIVE APPLYING APPARATUS AND METHOD 2 Sheets-Sheet 2 Filed Sept. 19. 1960 lillll INVENTOR 6| 73 him: LABmmARb ATTORNEYS United States Patent 3,165,419 AHEESZVE APPLYENG APiARATUS AND NETHQD L La h mbard, 45 Qourtland St., Nashua, NH. Filed Sept. 19, 1960, Ser. No. 56503 13 Claims, (Cl. 93--52) This invention relates to an improved apparatus and method for sealing the glue laps of collapsed, tubular, folding cartons with fast setting, thermo type adhesives.

In the folding carton art it has long been customary to advance a plurality of flat box blanks individually and successively along the paper line of a box folding machine, to apply adhesive to the glue laps by means of a conventional adhesive pot and to then overfold the outer wall panels on the second and fourth creases to form a collapsed tubular carton. The adhesive used has been slow-setting whereby the adhesive could be applied when the blank was flat and the adhesive would not set before the wall panels could be overfolded, the overfolding operation usually requiring ten or more feet of blank travel and one or more seconds of time.

Of recent years there has been in increasing demand for special coated cartons, in place of the well known wax coatings, and especially for polyethylene coatings. Polyethylene coated cartons cannot usually be satisfactorily sealed with conventional adhesives. They can, however, be perfectly sealed by the use of fast setting thermo type adhesives, if the surfaces to be adhered can be brought together before the adhesive sets, that is in a fraction of a second such as A or /8 second.

An object of this invention is to provide an apparatus and method for roller activating an adhesive on, or roller applying an adhesive to the glue lap of cartons advancing through a folding machine when the cartons are substantially folded into collapsed tubular form on the first and third creases thereof so that only to degrees of overfold remains to be accomplished thereafter. This final overfold consumes only a fraction of a second and permits the use of very fast setting adhesives.

Another object of the invention is to provide a machine for forming collapsed tubular boxes in which the box blanks are over-folded substantially into a flat tube on the first and third creases thereof in a major folding zone, a strip of fast setting adhesive is roller transferred and metered onto the glue laps within a narrow opening at the edge of the tube and the tube then immediately pressed into fiat sealed configuration.

A further object of the invention is to provide a novel adhesive pot for roller applying a metered strip of adhesive to substantially flat tubular cartons, the pot being air sealed, heated and including a driven adhesive applying disc, slightly inclined from the horizontal, whereby the low side is immersed in the adhesive and the high side projects into a narrow opening at an edge scam in blanks advanced thereby.

Still another object of the invention is to provide a machine for roller applying fast setting thermo type adhesive to the glue laps of polyethylene coated collapsed tubular cartons just before the cartons are pressed into fiat, tubular shape on the first and third creases thereof, thereby adhesively uniting the side edge of the flat collapsed carton in an extremely short path of blank travel.

A still further object or" the invention is to provide an adhesive pot with an adhesive applying disc, slightly tilted from the horizontal, in combination with a panel supporting sword arranged to maintain a narrow side edge opening in collapsed tubular blanks to receive the adhesive applying portion of the disc as the blanks travel past the adhesive pot.

A still further object of the invention is to provide means for roller applying a fast setting, hot melt, adhesive composition into a longitudinal edge opening of nearly overfolded, coated, box blanks for adhesively uniting the blanks int-o collapsed, tubular boxes in combination with a panel supportnig sword, glue lap and panel guides and means for controlling the thickness of the adhesive coating whereby the boxes are fiat, collapsed tubes before the adhesive has time to set.

Other objects and advantages of the invention will be apparent from the claims, the description of the drawings and from the drawings in which FIG. 1 is a diagrammatic plan View of a machine incorporating the invention,

FIGS. 2-8 are diagrammatic end views of the successive folding and adhesive applying steps accomplished by the machine of FIG. 1,

FIG. 9 is an enlarged top plan view of the adhesive applying means of the invention, and

FIG. 10 is an end view in section on line 1tll(} of FIG. 9,

FIG. 11 is a fragmentary view of a modification, similar to FIG. 10, but on an enlarged scale, and

P16. 12 is a fragmentary side view, in section, of the doctor blade means of the invention,

In FIG. 1 a machine 25 is illustrated of a type well known in the art and designed to overfold a plurality of flat box blanks such as 21, individually and successively into fiat, collapsed, tubular boxes, or cartons, 22 and to adhesively unite the glue lap of each carton to the fourth wall panel thereof. In conventional folding machines the adhesive applying zone is usually close to the feed zone in order to apply a coating of adhesive to the glue lap, and sometimes to a corresponding strip on the fourth panel, while these elements are still flat on the paper line. In the machine 2%, of this invention, however, the adhesive applying zone 23 is located in rear of a major folding zone 24 and just in advance of a minor folding zone 25. The term major folding zone as used herein is intended to mean a longitudinally extending portion of the paper line 25 wherein the glue lap and third and fourth panels of the blanks 21 are overfolded laterally on the first and third creases respectively through arcs of considerably more than and preferably through arcs of at least into substantially collapsed tubular form. In the major folding zone, therefore, the blanks are overfolded through the major portion of an angle of and nearly through the entire angle of 180. The term minor folding zone as used herein is intended to mean that portion of the paper line 26 in which the blanks are further folded through the remaining portion of an angle of 180 until the blanks have become fiat, collapsed, tubular cartons, as at 22.

The feed zone 27 and the stacking zone 23 may be part of machine 2% or may be separate machines, both being well known in the treade and forming no part of this invention. Each fiat box blank 21 includes first, second, third and fourth crease, or score lines 31, 32, 33 and 3.4 which extend longitudinally thereof and define a glue lap 35 and first, second, third and fourth wall panels 35, 37, 38 and 39. There may also be leading and trailing flaps on each blank. 21 for serving as a bottom and a top for the box but these have not been shown for clarity. it will be understood that the blanks 21 in the prior art were formed into collapsed, tubular shape by overfolding the outer panels 36 and 39, on the second and fourth crease lines 32 and 34 to overlie the inner panels 37 and 35, the glue lap 35 being glued to the outer edge portion of wall panel 39. Such overfolding may be accomplish-ed by twisted folder belts while the blanks are advanced by the frictional grip of upper and lower carrier belts in an untimed manner and with a high speed flow. It has been found to be relatively slow and unsatisfactory to attempt to adhesively unite coated car'- tons with a hot melt adhesive when the blanks are folded in this manner for the reason that the adhesive must be applied too early in the folding operation and tends to set before the fold can be completed.

In this invention the flat blanks 21 are, therefore, overfolded on the first and third crease lines 31 and 33 so that inner panel 38 and outer panel 39 overlie inner panel 37 and outer panel 36 with the glue lap 35 overfolded b neath the outer edge portion of outer panel 39. The blank advancing means 41 in the major folding zone 24 includes at least one pair of opposed upper and lower friction carrier belts 42 and 43 preferably laterally aligned to engage the blanks 21 along the second crease line 32. The blanks 21 received from feed zone 27, individually and successively in a known manner are thus advanced individually and successivel in untimed relation, through zone 24 and into adhesive applying zone 23. A twisted folder belt 44 is provided in the major folding zone 24 to overfold the panels 33 and 39 of the blanks 21 through an arc of at least 170 and preferably to overfold the panel 38 through the entire overfold arc of 180. Another twisted folder belt 45 is provided, in major folding zone 24, to overfold the glue lap 35 through an arc of at least 160 to 170 and thereby create a nearly completed collapsed tubular box to which adhesive has not yet been applied. The twisted folder belts 44 and 45, together a with the conventional drive pulleys, idler pulleys and power trains, not shown in detail since they are well known, comprise the major folding means 46 in the major folding zone 24.

Panel support means extends longitudin ally of the major folding zone 24 and the adhesive applying zone 23 in the form of an elongated sword, or bar, 51 supported at one end 52 on the frame 53 of machine 20 and unsupported at its free terminal end 54. Preferably the sword 51 is laterally aligned with the path of the portion of the outer panel 36 just inside the nearly overfolded glue lap 35, and just above the upper face 55 of the panel 36. In this position the sword 51 intercepts the outer panel 39 as the panel 39 is overfolded through 180 by the belt 44 and maintains a longitudinal side edge opening 56 in each successive blank as the blank enters zone 23. Each panel 39 is thus supported at a fold angle of about 170 relative to the first panel 36 While the panels 37 and 38 are in fiatwise engagement with each other as shown in FIG. 6. At this point the glue lap 35 has been overfolded through an angle of at least 160 so that it has been caught under the outer edge portion 57 of panel 39 and so that the edge 56 is of recumbent V configuration.

Adhesive roller applying means 60 is provided in the zone 23 for roller applying a layer of liquid adhesive to glue lap 35 just in advance of the minor folding zone 25. Means 60 comprises an adhesive pot 61 mounted on the frame 53 at one side of the longitudinal path of blanks 21 along paper line 26. The housing 62 of pot 61 includes an adhesive reservoir 63 for containing a fast setting,

thermo type adhesive such as Thermo-Grip a hot melt adhesive made by B. B. Chemical Company, Cambridge, Mass, and an aperture 64 in one wall 65 of the housing. Suitable electric resistance heating elements 66 are contained in'housing 62 for maintaining the liquid adhesive in reservoir 63 at well above the melting point of the composition. The reservoir 63 is filled with hot melt adhesive, with no air space above the level of the liquid, to prevent oxidation. It is fed with adhesive through'conduit 67. by controlled pumping from an extruder not shown. all in a manner well known in the art and similar to a conventional plastic extrusion machine. A shaft 68 is journalled in the top of housing 62 to revolve on an axis slightly inclined from the vertical, for example, from the vertical. A .drive gear 69 is fixed to the end 71 of shaft 68 outside housing 62, and is driven by any suitable power train connected to the drive mechanism of the machine 20, in a manner well known in the art and, therefore, not shown.

A rotary adhesive applicator 72, forms part of means 60 and projects over the path of the blanks 21, along paper line 26 to roll transfer adhesive from reservoir 63 to the overfolded glue laps 35 of each successive blank advanced through the zone 23. Preferably applicator 72 is a flat disc 73 fixed to the end 7 4 of shaft 68 within housing 62 and rotatable in a plane slightly inclined from the horizontal, for example, 10 from the horizontal. Hie low side 75 of the tilted disc 73 is below the level of the ad hesive in reservoir 63 whereby the disc rim portion 76 is supplied with a coating of the liquid adhesive. The high side 77 of the tilted disc 73 extends through the aperture 64 and projects beyond the Wall 65 to transfer the adhesive coating to the glue laps of the blanks, within the longitudinal edge openings 56 thereof. The rim portion 76 is provided with a bevelled edge 78 having at least one annular, penpiheral coating face 7% angularly disposed relative to a plane normal to the axis of the disc 73 and arranged to coat the glue laps 35. Preferably, however, the edge 755 is double bevelled with an isosceles triangular cross section and with a peripheral coating face 81 as Well as the coating face 79 whereby the underface of the panels 3% may be coated if, and when, desired.

Final folding means 82. is provided in the minor folding zone 25' in the form of a folder bar 83 mounted on frame 53 and extending longitudinally from disc 73 through the zone 25. A lower carrier belt 84 is also provided in zones 23 and 24 for supporting the blanks on one side thereof while the blanks are advanced through zones 23 and 24 by the frictional grip of the opposed upper and lower carrier belts 85 and 86 on the other side of the blanks. The belts $4, 85 and 86 are synchronized with the carrier belts 42 and 43, and the twist belts 44 and to advance the blanks through the machine 20 at a sped of about ninety blanks per minute and deliver the blanks as completed, collapsed tubular cartons into the stacking zone 28. The longitudinal edge opening 56 in each blank is closed so rapidly, after the adhesive is applied to the glue lap 35, for example in about V of a second and in about ten inches of blank travel, that a fast setting adhesive will not set before the blank is completely flat and collapsed.

As shown in FIGS. 9 and 10 a pair of longitudinally extending back-up faces 90 and 91 are preferably provided in the adhesive applying zone 23 for guiding the glue lap 35 and the corresponding portion of panel 39 into coating contact with the angular faces 70 and 81 of the adhesive disc 73. The face 90, is formed on a back-up sword 92, having one end 93 mounted on frame 53 and the other end 94 free and unsupported. The face 91, is formed on a back-up sword 95, which can be a separate member if desired, but which, for convenience, is shown as integral with the sword 51 and supported thereby.

As shown in FIG. 11, when it is desired that only the glue lap 35 be coated with adhesive the backup sword, or guide, is raised slightly away from the face 81 of the disc 73 and a panel supporting sword 96, corresponding to sword 51, is mounted on adhesive pot 61 to mask face 81 and prevent the coating thereof. As best shown in FIG. 9 doctor blade means 93 is carried by housing 62 of the adhesive pot 61 just inside the aperture 64. Means 98 preferably is in the form of a single blade 99, having a slot 100 which conforms in interior configuration to the exterior'configuration of the disc rim portion 76 including the beveled edge 78. Thus the beveled interior edges 101 and 102 of the slot 100 scrape the bevelled faces 79 and 31 of the disc 73 and the parallel interior edges 103 and 104 of the blade scape the parallel faces 105 and 106 of the disc. The blade 99 is slidable toward and away from the disc 73, and fixed in place by suitable set screw 107, thereby varying the space between the edges 101 and 162 and the face 79 and 81 to meter the thickness of the adhesive coating thereon. The means 98, also prevents leakage of the adhesive from the reservoir and tends to prevent the admission of air through the aperture 64.

This invention is illustrated on a box folding machine of the folder belt type but it is not intended to be limited to the same. The inventive concept can be applied to machines of the carrier chain type and to machines which use other than twisted belts for folding. It can also be used to seal already flattened collapsed, tubular cartons by arranging the sword 51 to create a longitudinal edge opening 56 thereon prior to arrival of the blanks at the disc 73. The tilted disc 73 and the side edge sealing described above have been found to result in practically perfect adhesive uniting and sealing of coated blanks with fast setting adhesives. Applying hot melt adhesives to the blanks while the panel 39 is folded through only a 90 angle or attempting to apply the hot melt adhesive when the blanks are folded on the second and fourth creases nearly through an angle of 180 increases the dwell of the adhesive on either the blanks or the adhesive applicator, tends to permit the adhesive to set before blanks can be fully folded or requires projection application of adhesive with its dripping and plugging problems.

The essence of this invention is the concept of sealing flat tubular cartons when the glue lap and third and fourth panels have been substantially overfolded through a one hundred eighty degree angle on the glue lap, or first crease, and on the third crease to substantially overlie the first and second panels. While I prefer to advance the blanks in a horizontal plane, it will be understood that they could be advanced in a vertical plane, or upside down, by known means. Similarly while I prefer to use adhesive applicator means 69 for hot melt adhesives, there are blank coatings which themselves are adhesive when melted. in such case, the sealing means can be simply the applicator 72, as shown diag ammatically in FIG. 6, with both faces '79 and S1 heated to well above the melting point of the coating by means'such as 66 (FIG. 11) or any other convenient means. Thus the coatings on each successive blank will be remelted to an adhesive state at the longitudinal edge space, gap or opening 56 and the glue lap and pane-ls then pressed into final fold form in the minor overfolding zone.

:1 claim:

1. A machine for forming collapsed tubular boxes from flat box blanks of the type 'having a first, second, third and fourth crease defining a glue lap and a first, second, third and fourth wall panel, said machine comprising means for advancing a plurality of said blanks individually and successively along a long tudinal path through a major folding zone, an adhesive applying zone and a minor folding zone; major folding means, in said major folding zone, for overfolding each successive blank substantially into collapsed tubular form with the glue lap and the third and fourth panels substantially overfolded on said first and third creases respectively to substantially overlie the first and second panels thereof; panel support means in said adhesive applying zone, in the arcuate folding path of the overfolded fourth wall panel of each successive blank for supporting said panel at a spaced distance from said overfolded glue lap and from the first panel thereof to maintain a longitudinal side edge opening between the overfolded glue lap and said overfolded fourth panel; adhesive roller applying means in said adhesive applying zone, said means including a heated, air sealed, adhesive pot having a driven rotary adhesive applicator projecting into said blank path and into the said longitudinal side edge opening of each successive blank for roller transferring a coating of adhesive to the overfolded glue lap thereof and final folding means in said minor folding zone for folding and pressing said fourth panel onto said glue lap for adhesively uniting the same and forming a completed tubular box.

2. A machine as specified in claim 1 wherein the means for advancing said blanks through said adhesive applying zone comprises opposed upper and lower carrier belts in frictional engagement with the overfolded second and third wall panels of each said blank.

3. A machine as specified in claim v1 wherein said panel support means comprises a longitudinally extending sword laterally aligned with the path of the said longitudinal side edge openings in each successive blank for masking the adjacent underface of the fourth panels thereof from said adhesive applicator.

4. A machine as specified in claim 1 wherein said panel support means comprises a longitudinally extending sword having two angularly related, fiat, upper faces, one face laterally aligned with the path of said overfolded glue lap for backing up the same and the other face laterally aligned with the path of a portion of said fourth panel just inside said side edge opening for supporting said panel.

5. A machine as specified in claim 1 wherein the rotary adhesive applicator of said adhesive applying means is a discus shaped adhesive wheel rotating in a plane slightly inclined from the horizontal with the lower side thereof air seared within, and below the level of the adhesive in, said pot and the higher side thereof projecting into the path of the longitudinal side edge openings of said blanks.

6. A machine as specified in claim 1 wherein said adhesive applicator is a flat disc air sealed within said adhesive pot and having a pair of outwardly extending, bevel edge faces at the rim thereof, a peripheral portion of said rim extending outside said pot and being adapted to simultaneously apply a layer of adhesive to the faces of said glue lap and fourth panel in the longitudinal side edge opening of said blanks.

'7. A machine as specified in claim 1 plus a pair of Iongitudinally extending back-up swords, each laterally aligned with the longitudinal side edge openings of said blanks and arranged to back-up the glue lap and fourth panel of said blanks while adhesive is applied thereto by said adhesive applicator.

8. Apparatus for sealing coated box blanks into collapsed tubular form, as said blank-s are advanced individually and successively along a path through the overfolding zone and adhesive applying zone of a box forming machine, said apparatus comprising means for overfolding the glue lap on the first crease and the third and a fourth panels on the third crease of each blank in said overiolding zone; panel support means in said overfolding zone extending through said adhesive applying zone, said panel support means being in the folding path of the terminal edge portion of each fourth panel of said blanks to intercept the same and support said panel at a spaced angular distance of about 10 degrees from the overfolded glue lap of the said blank and adhesive roller applying means in said adhesive applying zone, said means including a rol er adhesive applicator extending laterally into the said space between said overfolded fourth panel and glue lap for roller transferring a coating of adhesive thereto whereby adhesive is applied to the overfolded glue laps of said blanks just before the completion of the overfolding of the panels thereof into collapsed tubular form.

9. A combination as specified in claim 8 wherein said adhesive applying means includes a substantially air sealed adhesive reservoir for a hot melt, adhesive composition and heating mechanism for maintaining the composition in said reservoir at a temperature above the melting point thereof and an adhesive applicator including a disc rota-table in a nearly horizontal plane with the lower side thereof substantially air sealed within said reservoir and the higher side thereof projecting outside said reservoir into said space and drive means for rotating said disc.

10. The method of adhesively uniting polyethylene coated blanks into flat collapsed tubular cartons by means of fast setting, thermo type adhesives, said method compris ng the steps of advancing said blanks individually and successively along a path through an adhesive applying zone; substantially overfolding the glue lap of each said blank on the first crease and the third and fourth panels of each said blank on the third crease through fold angles of about in advance of said adhesive applying zone, to thereby create a longitudinal extending, side edge opening of about 10 of fold along the overfolded glue lap portion of said blanks; maintaining said opening while roll transferring and metering a coating of fast setting, thermo type adhesive to the glue laps of each successive blank, within said longitudinal opening, in said adhesive applying zone and then flattening each successive blank into a collapsed tubular carton as said blank leaves said adhesive applying zone.

1 1. A machine for forming collapsed tubular boxes from flat box blanks of the type having a first, second, third and fourth crease defining a glue lap and a first, second, third and fourth wall panel, said machine comprising means for advancing a plurality of said blanks individually and successively along a longitudinal path through a major folding zone, an adhesive applying zone and a minor folding zone; major folding means, in said major folding zone, for overfolding each successive blank substantially into collapsed tubular form with the glue lap and the third and fourth panels thereof folded through arcuate paths of at least 160 degrees on said first and third creases respectively; panel support means in said adhesive applying zone, in the arcuate folding path of the fourth wall panel of each successive blank for supporting said panel at a fold angle of about 170 degrees relative to the first panel thereof to maintain a longitudinal side edge opening between the overfolded glue lap and said overfold fourth panel; adhesive roller applying means in said adhesive applying zone, said means including a substantially air sealed, heated adhesive pot having a driven, adhesive transferring disc rotating in said pot and having a peripheral portion projecting over said blank path and into the said longitudinal edge opening of each successive blank for transferring a coating of adhesive to the overfolded glue lap thereof and final folding means in said minor folding zone for folding and pressing said fourth panel onto said glue lap for adhesively uniting the same and forming a completed tubular box.

12.; Apparatus for folding and sealing coated box blanks into collapsed tubular form, the coating of said blanks being adhesive when heated to the melting point thereof, said apparatus comprising means for advancing said blanks individually and successively along a path through a major overfolding zone, a sealing zone and a minor overfolding zone; folding means along said path in said overfolding zone for substantially overfolding the glue laps of said blanks on the first crease and the third and fourth panels of said blanks on the third crease to substantially overlie the first and second panels thereof; panel support means mounted along said path in said overfol-ding and sealing zones, said panel support means being in the overfold path of each said fourth panel to intercept and support the same with a longitudinal side edge gap between said overfolded glue lap and said overfolded fourth panel; sealing means along said path in said sealing zone, said sealing means including heating means extending into the longitudinal edge gap of each successive blank for remelting, to adhesive state, the coating on, the opposed faces of said glue lap and fourth panel desired to be sealed and minor overfolding means in said minor overfolding zone for folding and pressing said glue lap and fourth panel together to finally and firmly seal said blanks into collapsed tubular form.

13. The method of adhesively uniting coated blanks into flat, collapsed, tubular cartons while said blanks are advancing along a path which method comprises the steps of first substantially overfolding the glue lap and the third and fourth panels of each said blank, individually and successively, on the first and third creases thereof, into collapsed tubular form, with the coated face of the overfolded glue lap in close proximity to the corresponding coated face of the overfolded fourth panel, but unconnected thereto; then temporarily maintaining a narrow side'edge opening between said overfolded glue lap and fourth panel while applying heat, from within said opening, to the coatings on the said faces to activate the same to an adhesive state and finally, completing the folding and sealing of said blanks into flat tubular cartons, by applying pressure along said faces to seal the glue lap edges of said cartons.

References Cited in the file of this patent UNITED STATES PATENTS 2,289,798 Nadeau et al. July 14, 1942 2,572,047 7 Neal Oct. 23, 1951 2,782,755 Pospiszel Feb. 26, 1957 2,783,693 Felber Mar. 5, 1957 2,898,816 Keely Aug. 11, 9 2,899,873 La Bombard Aug. 18, 1959 3,001,505 Novick Sept. 26, 1961 

1. A MACHINE FOR FORMING COLLAPSED TUBULAR BOXES FROM FLAT BOX BLANKS OF THE TYPE HAVING A FIRST, SECOND, THIRD AND FOURTH CREASE DEFINING A GLUE LAP AND A FIRST, SECOND, THIRD AND FOURTH WALL PANEL, SAID MACHINE COMPRISING MEANS FOR ADVANCING A PLURALITY OF SAID BLANKS INDIVIDUALLY AND SUCCESSIVELY ALONG A LONGITUDINAL PATH THROUGH A MAJOR FOLDING ZONE, AN ADHESIVE APPLYING ZONE AND A MINOR FOLDING ZONE; MAJOR FOLDING MEANS, IN SAID MAJOR FOLDING ZONE, FOR OVERFOLDING EACH SUCCESSIVE BLANK SUBSTANTIALLY INTO COLLAPSED TUBULAR FORM WITH THE GLUE LAP AND THE THIRD AND FOURTH PANELS SUBSTANTIALLY OVERFOLDED ON SAID FIRST AND THIRD CREASES RESPECTIVELY TO SUBSTANTIALLY OVERLIE THE FIRST AND SECOND PANELS THEREOF; PANEL SUPPORT MEANS IN SAID ADHESIVE APPLYING ZONE, IN THE ARCUATE FOLDING PATH OF THE OVERFOLDED FOURTH WALL PANEL OF EACH SUCCESSIVE BLANK FOR SUPPORTING SAID PANEL AT ASPACED DISTANCE FROM SAID OVERFOLDED GLUE LAP AND FROM THE FIRST PANEL THEREOF TO MAINTAIN A LONGITUDINAL SIDE EDGE OPENING BETWEEN THE OVERFOLDED GLUE LAP AND SAID OVERFOLDED FOURTH PANEL; ADHESIVE ROLLER APPLYING MEANS IN SAID ADHESIVE APPLYING ZONE, SAID MEANS INCLUDING A HEATED, AIR SEALED, ADHESIVE POT HAVING A DRIVEN ROTARY ADHESIVE APPLICATOR PROJECTING INTO SAID BLANK PATH AND INTO THE SAID LONGITUDINAL SIDE EDGE OPENING OF EACH SUCCESSIVE BLANK FOR ROLLER TRANSFERRING A COATING OF ADHESIVE TO THE OVERFOLDED GLUE LAP THEREOF AND FINAL FOLDING MEANS IN SAID MINOR FOLDING ZONE FOR FOLDING AND PRESSING SAID FOURTH PANEL ONTO SAID GLUE LAP FOR ADHESIVELY UNITING THE SAME AND FORMING A COMPLETED TUBULAR BOX. 